This invention relates to devices for illuminating a specimen to be viewed through a microscope and more particularly to a device which will adjustably filter and polarize the light used for illumination so as to provide simply for the enhanced viewing of fluorescense.
Advances in medical research have provided the health care provider with an ever increasing number of analytical and diagnostic tools which are indispensable aids in arriving at a proper diagnosis of conditions and ailments. Of particular interest here is the growing use of immunoassay analytical techniques. Body fluids, serums and the like can now be tested for the presence of immune complexes by reacting the fluid with a highly specific protein to absorb the immune complex, if present, and subsequently conducting a further reaction with a reactant, such as anti-human IgG coupled with an enzyme, as with the ELISA technique, or by fluorescence-immunoassay (FITC). The foregoing, referred to as the ELISA assay, is described in The Enzyme Linked Immunosorbent Assay by Bidwell and Bartlett (1979); the latter in "FLUOR-ANTIBODY MICROSCOPY" by William B. Cherry, Ph.D; USDHEW, Center for Disease Control, Atlanta, Ga.-June, 1977.
A wide variety of fluorochromes have been employed which when reacted will produce conjugates which fluoresce when excited by specific wave lengths of light, particularly in the near-ultraviolet. The presence, then, of a particular visible color of fluorescence will indicate the presence and amount of immune complex present originally in the sample being analyzed. Microscope equipment has been available for such analytical work which has enabled the laboratory to successfully assay many of the immune complexes identified as useful for diagnosis of a wide variety of conditions. Some instruments have been developed to provide for a spectrophotometric measurement of emission fluorescence, results of which can be quantitatively correlated to presence of certain immune complexes. Other equipment, currently employed in immuno-fluorescence work, is characterized as "integrated" and "unimodular" and is uniformly sophisticated and extremely expensive. However, since the singular requirement for qualitative estimations is in the production of the distinctive type of fluorescence, it has been desirable for there to be a special, properly filtered energy source that can independently operate with any existing microscope for viewing immunofluorescent preparations. Such a device would be extremely useful for the clinical laboratory and research lab facility. The illuminator of the present invention fits such criteria in that it is not unimodular nor integrated with any specific microscope, and may be employed interchangeably with any commonly available microscope. Further, a less expensive article of laboratory equipment for these assays is desirable in order to contribute to the containment of health care costs while providing service which is consistent with the state of the art.
It is therefore an object of the present invention to provide an improved, low cost microscope illuminator adaptable to most microscopes for viewing immunofluorescence, and to provide novel structure for the illuminator so as to improve the ability, and therefore the accuracy, of average laboratory personnel to visually distinguish the particular fluorescence from the variety of colors and background light which can be observed in particular samples.